Floating dock structures are widely used in marinas and boat harbors as a means for mooring watercraft and as wave-attenuation devices. Typically, floating dock structures are constructed by interconnecting individual or modular float sections. Historically, concrete float units were cast as six-sided modules, with integral bottoms. These modules, which were usually about 8′ to 12′ long, were structurally interconnected using timber or steel members, called wales. Today, however, concrete floats are traditionally constructed as five-sided, monolithic structures that do not require the use of longitudinal structural members, such as disclosed in U.S. Pat. No. 6,450,737, the entire disclosure of which is incorporated herein by reference.
Regardless of whether a concrete float is constructed as a modular unit or a monolithic structure, a positive displacement element, such as expanded polystyrene foam (EPS), is typically positioned within an outer form and concrete is poured over and/or around the positive displacement element. Before the advent of EPS in block form, the inner form typically comprised a wax-treated, reinforced cardboard box member. Thus, the positive displacement element (and, previously, the cardboard box member) provides the internal form for forming the concrete structure and, after the concrete cures, is integrated into the structure of the concrete float.